Little white bump behind tonsil. when i scratch its went away.after 3 day same place coming back again i scratch with earbuds and its went what it is ?

Tonsil stone: You may be describing a tonsil stone. They tend to recur but are not typically pathologic. They can however contribute to bad breath and low grade sore throat/irritation in combo with lax oral hygiene. Try peroxide gargles to break attachment of tonsil stone to tonsil tissue and reduce food debris in tonsil folds. If more numerous, painful or other concern, see your primary care or ENT specialist

Tonsilith: Tonsils often contain pockets and they fill with debris and solidify and are called tonsil stones. These can be removed or sometimes dislodged by gargling. Because they block tonsillar secretions they can predispose you to infection.